+118723 okay I am going to try and help you learn this.
It is going to be 6.899 multiplied by 10 to the power of something. (exactly 1 non-zero digit in front of the point)
If 0.0006899 is more than one then the power will be positive. If it is less then 1 then the power will be negative. So what is it going to be + or - ?
Now: How many numbers does the point have to jump over to get from where it stated to where it needs to be? That is your power. What is it ?
Now you do it and tell me what you think the answer is. 
